Pavement lifter



Def 30, 1969 v. R. SODERLUND 3,486,795

PAVEMNT LIFTER s-Sheet 1 i 2 Sheet Filed Dec. 1s, 1967' uvvENToR. Vernon R. Soderlund MWL Artqrpeys Dec. 3o, A1969 R. som-:RLUN'D 3,486,795

PAVEMENT LIFTER Filed Dec. 13, 1967 2 Sheets-Sheet 2 Fig. 3

INVENTOR. odeZund Attorneys BY .Vernn R. S

United States Patent Office 3,486,795 Patented Dec. 30, 1969 3,486,795 PAVEMENT LIFTER Vernon R. Soderlund, 4330 Piedmont Ave., Oakland, Calif. 94611 Filed Dec. 13, 1967, Ser. No. 690,152 Int. Cl. E01c 23/00 U.S. Cl. 299-36 6 Claims ABSTRACT F THE DISCLOSURE This specification discloses a pavement lifter consisting of a frame mounted on a prime mover having horizontally spaced pavement engaging members mounted thereon and a lift blade mounted on the frame between and below the pavement engaging members for severing a strip of pavement from its subgrade in a continuous forward movement of the entire device.

BACKGROUND OF THE INVENTION SUMMARY The gist of the invention is the discovery that asphaltic concrete strips of pavement can be cut and lifted in a continuous strip by providing a lifting blade which is formed with an elevated central portion so as to cause the strip of pavement to arch as it is lifted. The arching applies tension transversely to the lifted pavement strip and thus the sides of the pavement strip sever in a neat straight line at the point of contact of the spaced ground engaging members much like a piece of paper can be torn along a straight edge.

Objects of the present invention are to provide a device which is:

(a) less expensive than present pavement cutting devices,

(b) lifts pavement faster with less expenditure of power,

(c) is safer by eliminating flying chips as the pavement is severed,

(d) constructed so as to practically eliminate equipment maintenance,

(e) is adapted for attachment to various types of prime movers such as crawler tractors, equipped with rear mounted ripper attachments, crawler or rubber tire tractors equipped with front end loaders or other prime movers especially designed for this attachment.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE l is a side elevation view of the device attached to a crawler tractor shown in phantom line.

FIGURE 2 is an enlarged side elevation view of the device shown in FIGURE l.

FIGURE 3 is a top plan view of the device shown in FIGURE l, with portions removed for purposes of clarity.

FIGURE 4 is a front elevation view of the device taken substantially along the line 4-4 in FIGURE 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pavement lifter of the present invention consists briefly of a frame 1 adapted for connection to a prime mover 2; a pair of spaced pavement engaging members 3 and 4 mounted on the frame and a lift blade '6 mounted on the frame between the pavement engaging members for severing a strip of pavement 7 from its subgrade 8 and having a centrally located raised portion 9 for elevating the middle portion of the severed strip of pavement.

The pavement lifter of the present invention may be attached to the front end loader bucket of a crawler or wheeled tractor and the pavement lifted directly into the bucket. Many trenches in street pavements are dug with tractors having front end loaders and back hoes. The present device attached to such a tractor would eliminate one piece of equipment and its operator, namely the selfpropelled drop chisel. As here shown the device is attached to the rear of a crawler tractor equipped with a ripper attachment 11 which is hydraulically raised and lowered. The only modification to the ripper is the removal of the ripper teeth.

Referring now to the details of construction of the device, the pavement engaging members may consist of any means for bearing down on the pavement on the outside edges of the strip to be severed. The members may be elongated skids or shoes, preferably a flange or knife edge should be provided to more clearly dene the edge of the cut. As here shown, the ground engaging members consist of a pair of metal wheels in which their rims are formed to provide a sharpened edge 12 and a sharpened edge 13 at the circumference. The wheels are rotatably mounted on an axle 14 aflixed in spaced relation by a sleeve 16 and cotter keys 17 and 18.

The lift blade may be iixedly mounted on the frame but preferably it is pivotally mounted to lift pavements of different thicknesses. As here shown, the blade is connected to the frame by pins 19 and 21 inserted through openings in strong backs 22 and 23 mounted beneath the side edges of the pan 20 to give it the required rigidity. The lift blade itself is formed with a cutting edge 24 which is preferably tapered having beveled faces 26 and 27 and is also slightly pointed by providing tapered faces 28 and 29. The lift blade need not be very long but should be approximately as wide as the space between the spaced ground engaging wheels. Additional length of the pan can be approximately as wide as the space between the spread fracturing when the pavement is dropped or the extension can lift the pavement directly into a loader bucket or onto a conveyor or even directly into a truck trailing the device.

As stated above, the central portion of the lift blade is raised to cause the severed pavement to form an arch as it is lifted. This transverse curving of the pavement creates tension of the asphaltic concrete at the point where wheels contact the pavement and assist in the severing at the edges. Various means can be employed to cause the bending of the pavement but as shown in the drawing, an angle iron having sides 31 and 32 is welded to the pan near the forward edge. The angle nose has tapered edges 33 and 34 to assist penetration of the blade.

As shown in the drawings, the lift blade is pivotally mounted on the frame. A pair of suspension -bars 25 and 35 are connected to the axle at one end and to a pair of uprights 36 and 37 at the other. The uprights are provided with a series of spaced openings 38 through which pins 41 and 42 are inserted to register with openings in the suspension bars. The lift blade is pivotally connected to the suspension bars by trunnion pins 43 and 44 mounted on pan brackets 46 and 47. Connected to the edges of the lift blade or pan. As shown in FIG- URE 2, the uprights tilt forwardly and rearwardly as the lift blade is raised and lowered. Note further that the cutting edge of the blade is approximately located directly beneath the ground engaging wheels.

The manner in which the lift blade is connected to the prime mover is not a part of the invention and depends entirely upon what type of equipment is used to move the device. As shown here, the device is constructed with a box frame 48 which is connected to a standard ripper attachment on a crawler tractor by pins 49. Plate 51 beneath the ripper attachment prevents upward thrust, side plates 52 and.53 prevent side thrust.

In operation, the lift blade is set to the desired depth by moving the suspension bar to the desired height on the upright members. The hydraulic ripper attachment on the tractor is then lowered as the tractor moves forward. The device is lowered until the ground engaging members or wheels are forced against the pavement so as to prevent uplifting of the sides of the pavement as the lift blade lifts the pavement. As the tractor moves forwardly, the cutting edge of the lift blade separates the layer of pavement from either an old layer or pavement or it lifts the entire pavement from the subgrade. It has been found that where layers of asphaltic concrete are unusually thick, the device may be used to strip one layer of pavement at a time. If the pavement is to be merely separated from the subgrade and dropped back in place -without fragmenting, a short pan is suitable. If it is desired to fracture the pavement, a longer lift blade may be provided so that the pavement is elevated and then dropped oft" the rear of the lift pan. If the pavement is to be loaded directly into trucks or into a front end loader, the pan may be extended from the rear. The asphaltic concrete is sufficiently tenacious as to remain in one strip while moving up the lift pan.

I claim:

1. A device for severing a strip of flexible pavement from its subgrade in a continuous forward movement of the entire device comprising:

(a) a frame adapted for connection to a prime mover;

(b) a pair of spaced pavement engaging members mounted on the frame engaging the pavement at points at the side edges of said strip; and

(c) means mounted on said frame between said pavement engaging members consisting of:

(l) a cutting edge mounted substantially directly below said pavement engaging wheels and at a substantially right angle to the directon of movement and having a width substantially equal to the distance between said pavement engaging members for severing a strip of pavement from its subgrade,

(2) a lift blade having a width substantially equal to said blade and being continuous with said cutting edge and extending upwardly and rearwardly for elevating said severed strip above said subgrade, and

(3) an elevating member located near the middle of said lift blade and immediately rearwardly of said cutting edge and having a center portion tapered upwardly from said cutting edge and having side portions tapered laterally for elevating the middle portion of said strip more rapidly and to a greater elevation initially than the edges of the severed strip causing the edges of said strip to be placed in tension and to tear away from the unsevered pavement.

2. A device as described in claim 1 in which said pavement engaging members consist of a pair of horizontally spaced skids having elongated tapered portions for dening the sides of the severed pavement strip.

3. A device as described in claim 1 wherein said pavement engaging members consist of a pair of spaced pavement engaging wheels having flanges for severing and defining the side edges of the severed pavement strip.

4. A device as described in claim 1 in which the lift `blade is pivotally mounted to the frame; and adjustable means connected to the frame and the lift blade for selectable adjustment of the cutting edge to varying depths below the top surface of the pavement for severing and lifting pavements of different thicknesses.

5. A device as described in claim 1 in which the lift blade extends rearwardly and upwardly for elevating the severed pavement directly into a truck for removal.

6. A device for severing a strip of flexible pavement from its subgrade in a continuous forward movement of said entire device comprising:

(a) a frame adapted for connection to a prime mover;

(b) a pair of spaced wheels mounted on said frame and engaging said pavement at the sides of said strip to be severed and having annular surfaces tapered to form a cutting edge on the inside edge of each wheel;

(c) a lift blade mounted on said frame between said lwheels including an elongated angle member mounted substantially midway between the wheels with its sides extending angularly upwardly and its forward edge tapered to receive and elevate the central portion of the severed pavement strip;

(dl)D the frame consisting of a pair of spaced side memers;

(e) the litt blade being pivotally mounted at its rearward end to `be spaced side members and having upwardly extending brackets mounted between the pivot ends and the cutting edge;

(f) a pair of upwardly extending members pivotally mounted on the rearward portions of the spaced side members and having means for attachment at selectable elevations; and

(g) a pair of suspension bars pivotally mounted at their forward ends on the forwards end of the frame side members and their rearward ends removably attached to the upwardly extending members, and having journal means for pivotally receiving the brackets attached to the lift blade.

References Cited UNITED STATES PATENTS 828,734 8/1906 Gammie 299-37 2,768,794 l0/l956 Putnam 299--36 X 2,878,002 3/1959 Haley 299-36 ERNEST R. PURSER, Primary Examiner 

